Forming of containers from bags



July 12, 1966 w. c ou 3,260,170

- FORMING OF CONTAINERS FROM BAGS Filed Dec. 26, 1965 4 Sheets-Sheet l Q 50 35 60 71a 77b F/G. 2- -F G. 3.-

-F/ G.4- *F/Gj- INVE NTOR;

RONALD WILLlAM BARRACLOUGH July 12, 1966 R. w. BARRACLOUGH 3,260,170

FORMING OF CONTAINERS FROM BAGS Filed Dec. 26, 1965 4 Sheets-Sheet 2 INVENTOR; RONALD WILLIAM BARRACLOUGH y/w MM July 12, 1966 R. w. BARRACLOUGH 3,260,170

FORMING OF CONTAINERS FROM BAGS Filed Dec. 26, 1963 4 Sheets-Sheet 5 o :3 C)- 48- 49 47 44 42 53 N Q Q) 73 72c D 58 52 0 F/G. l2. 52a

INVENTOR: RONALD WILLIAM BARRACLOUGH WWW July 12, 1966 R. w. BARRACLOUGH FORMING OF CONTAINERS FROM BAGS Filed Dec. 26, 1963 4 Sheets-Sheet 4 Q E I Q Q k I INVENTOR:

RONALD WILLIAM BARRACLOUGH BYJ M H rrv.

United States Patent 3,260,170 FORMING OF CONTAINERS FROM BAGS Ronald William Barraclough, Southport, England, assignor of one-half to R. W. Barraclough Limited, Southport,

England, a British company Filed Dec. 26, 1963, Ser. No. 333,377 Claims priority, application Great Britain, Jan. 5, 1963, 604/63 8 Claims. (Cl. 93-8) The present invention relates to containers having block bottoms and more particularly to the forming of such containers from gusseted bags.

It is known to form a bag from a length of gusseted tubing, comprising two plane faces connected by two gusseted side walls, by attaching together the two plane faces near an end region of the length and securing the end regions of the gusseted side walls between the attached regions of the plane faces.

A bag of the type referred to above can be conveniently formed from a length of heat sealable gusseted tubing by collapsing the gusseted side walls, so that the plane faces of the tube lies in close relationship with the gusseted side walls between them, and then applying heat and pressure to a transverse section of the tubing to fuse the plane faces and the gusseted side walls together in a single weld over said section.

The object of the present invention is to provide an arrangement for forming a bag having gusseted side walls into a block bottom container.

According to one aspect of the invention, in apparatus for forming a container with a block bottom from a length of gusseted tubing having one end closed, support means are provided for supporting the length of gusseted tubing in the region of the upper open end thereof and first and second members define a restricted opening through which the lower regions of the length of tubing pass so that the closed end of the length of tubing is in parallel relationship to said restricted opening whereby on the inflation of the length of tubing by the introduction of gas into the open end thereof the lower regions of the length of tubing are drawn upwardly through said restricted opening to enable a folding action to take place to give a block bottom to the containe-r so formed.

According to another aspect of the invention, in apparatus for forming a container with a block bottom from a length of gusseted tubing having one end closed, support means are provided for supporting the length of gusseted tubing in the region of the upper open end thereof and the lower regions of the length oftubing adjacent the closed-end thereof are positioned between two rollers arranged in parallel relationship to said closed end whereby on the inflation of the length of tubing by the introduction of gas into the open end thereof the lower regions of the length of tubing are drawn upwardly between the rollers so that a folding action takes place to give a block bottom to the container so formed.

The invention will be better understood from the following description taken in conjunction with the accompanying drawings comprising FIGS. 1 to 13. In the drawings FIGS. 1 to 5 show various stages in the formation of a container having a block bottom,

FIG. 6 shows diagrammatically one embodiment for forming the block bottom,

FIG. 7 shows a section through the mouth of the bag and nozzle on the line IIII of FIG. 4,

FIG. 8 shows a plan view of the supporting means for the bag,

FIG. 9 shows a side view of the supporting means shown in FIG. 8,

Patented July 12, 1966 FIG. 10 shows a plan view of the supporting means from below, showing the jaws in the open condition,

FIG. 11 is a detail view of a section of the rear jaw lever assembly,

FIG. 12 is a side view of the blow open arrangement, and

FIG. 13 is a side view of another embodiment for forming a block bottom.

The invention has particular application to a machine for forming, charging and sealing containers made from a gusseted tube of semi-rigid material in which a flat or block bottom is required for the container. Such a machine is described and claimed in our Patent No. 3,112,588 but it is to be clearly understood that the invention is not limited to use with such a machine but can be employed in any machine for forming a container where a block bottom is required and where the material of the container has little rigidity.

In the machine described in our Patent No. 3,112,588 a circular turret has a plurality of gusseted tubing supporting means equally spaced about and projecting forwardly from its peripheral edge. An equal plurality of fixed stations are arranged equally spaced about the turret and the turret is arranged to be indexed through a predetermined angle to bring each gusseted tubing supporting means into alignment with a fixed station during dwell periods of the turret. It can therefore be seen that each supporting means passes each of the fixed stations during one complete revolution of the turret and after each indexing movement of the turret, the supporting means will be locked exactly opposite a fixed station.

Usually different operations take place at the different fixed stations. Thus at the first station, a continuous length of gusseted tubing is advanced until a predetermined length has been fed into the supporting means, whereupon a shearing arrangement is operative to sever the length of tubing which is now held along the upper edges by the supporting means. The tubing is held by the supporting means during the whole of the forming, charging and sealing operations.

The supporting means is now indexed by the turret to a second station where the lower end of the tubing is sealed thereby forming the tubing into a bag. In this operation the two parallel plane surfaces 11a and 11b (FIG. 1) of the bag and the gusseted side walls therebetween, 11c and 11d, are welded together in a single transverse seam He.

The supporting means are then indexed passed further fixed stations at which operations take place which are of no interest as far as the present invention is concerned. Eventually the supporting means are indexed to a fixed station at which the bag is inflated to form a container having a flat or block bottom, and it is at this station that the means according to the invention are applied.

At subsequent stations, the container is charged, the open end sealed and the charged and sealed container is discharged from the machine.

Before proceeding with a detailed description of the arrangement according to the invention, a description will be given of the supporting means for the container.

Thus referring to FIG. 8, the gusseted tubing supporting means, generaal-ly indicated by numeral 30 is secured to the peripheral flange 31a of the turret 31 and comprises two side jaws 32 and 33, pivotally mounted on a pin 30b and spring-loaded towards one another by a coil spring 34, and a back jaw 35 between said side jaws 32 and 33. The back jaw 35 is mounted on the upright limb of a bell crank lever 35a (FIG. 9) which lever 35a is pivotally mounted on a pin 35b between side walls 30d and 30e of turret 31 and the lever 35a is spring-loaded to urge back jaw 35 outwardly relative to the turret 31 by a coil spring 36. Bell crank lever 35a has a side projecting portion 35f (FIG. 11) and the jaw 35 has an abutment 35g (FIG. 9) projecting upwardly therefrom, parts 35 and 35g being individually adapted to be engaged by a push rod or the like from any one of the stations to cause jaw 35 to be rearwardly displaced against the tension of spring 36. Each of the side jaws 32 and 33 carries an inwardly directed shoe 32a and 33a (FIG. 8) respectively on its outer end, said shoes 32a and 33a presenting inner surfaces 32b and 33b respectively which cooperate with the foward edge 3511 of jaw 35 to form the gripping surfaces of the jaws. Each side jaw 32 and 33 also has a roller 32c and 330 respectively, which rollers are engaged by inclined surfaces 351' on the back jaw 35. In a closed position of the supporting means 30, jaw 35 tends to take up its forward position due to its spring 36. Jaws 32 and 33 are urged inwardly against the sides of jaw 35 by their spring 34, and the forward edge 3511 of jaw 35 applies a forward pressure against the surfaces 32b and 33b of the jaw shoes 32a and 33a respectively.

When a push rod or the like is advanced against part 351 and 35g, jaw 35 is rearwardly displaced against the tension of spring 36, jaws 32 and 33 remaining closed until the inclined surfaces 351' of jaw 35 engages rollers 32c and 330. Further rearward displacement of jaw 35 causes rollers 32c and 33c to be forced outwardly thereby opening jaws 32 and 33 against the tension of spring 34 The above sequence of operations is reversed as the jaw 35 is allowed to advance forwardly, that is, as jaw 35 advances rollers 32c and 330 ride down inclined faces 35 to allow jaws 32 and 33 to adopt a closed position and in the final stages of the advancement, jaw 35 advances to engage surface 32b and 33b.

- Reference will now be made to FIGS. 12 and 13 which shows the apparatus at the station where the container is inflated and block bottom formed. A casting 40 (FIG.

'12) presents pivot :pins 41 and 42 for pivotally supporting two levers 43 and 44. A nozzle mounting plate 45 is pivotally connected by pivot pins 46 and 47 to the ends of the levers 43 and 44. The link members 43 and 44 are arranged substantially parallel and the pitch between the two pivotal connections on each pivotal lever 43 and 44, Le. the pitch between pins 41 and 42 and the pitch between pins 46 and 47, is the same so that the vertical disposition of mounting plate 45 is always the same.

The plate 45 has a nozzle 48 pivotally mounted thereon by a pivot pin 45a and a coil spring 49 is provided for maintaining nozzle 48 in a substantially vertical position. Nozzle 48 is connected to a high pressure source (of air or other suitable gas) by way of a flexible conduit 50.

Pivotal lever 44 extends rearwardly beyond pivot pin 42 and is rotated in an anticlockwise direction by a push rod 51 actuated by a cam 52, a coil spring 53 being provided for causing the pivotal lever 44 to tend to rotate in a clockwise direction to maintain the said lever 44 in engagement with a push rod 51.

Casting 40 also pivotally supports an arm 54, which is pivotally connected at its upper end to a pad carrier 55, and a bell crank lever 56, which is pivotally connected near its mid region to casting 40, has one of its arms 56a, pivotally connected to the pad carrier 55 and its other arm 56b connected to a cam follower 57. The cam follower 57 is engaged by a cam 58 and is held in engagement with cam 58 by a coil spring 59.

The pitch of the two pivotal connections on pivotal arm 54 the same as the pitch of the mid-pivotal connection of hell crank lever 56 and the pad carrier pivotal connection on arm 56a, whereby the axis of pad carrier 55 remains substantially constant for all the positions thereof.

Pad carrier 55 has a substantially resilient pad 60 mounted on its forward end and a bearing bracket 61 slidahlv mounted on its upper regions, bracket 61 being loaded by a spring 62 towards the pad 60. A lever 63 is pivotally connected to bracket 61 by a pin 61a and a spring 64 causes lever 63 to tend to rotate in an anticlockwise direction. The lever 63 has an electromagnet 65 mounted near its rear end, which cooperates with a soft iron block 66 secured to the pad carrier 55, and a beak 63a is securely mounted on the forward end of lever 63.

A bracket 64 (FIG. 13) is secured to the underside of the structure 64a on which the casting 40 is mounted and has secured thereto a support plate 65. The support plate 65 is provided with a slot 66 and a support member 67 is adjustably secured to the support plate 65 by a nut and bolt, the latter passing through the slot. The position of the support member is thus adjustable to enable containers of different length to be accommodated by the machine. The support member 67 is provided with two bearings 68 and 69 through which an operating rod 70 passes freely. The support member 67 passes through an opening 71 in the side wall of the turret and carries at its end two pivotal bell crank levers 72 and 73; The arms 72a and 73a of the bell crank levers are-connected by a spring 74 which tends to draw the two arms together. The arms are held apart by two links 75 and 76 which are pivotally secured to the arms 72a and 73a, the other ends of the links being pivotally mounted on a pin 77a in the shackle 77 which is secured to the end of the operating rod 78. The other arms 72b and 73b of the levers 72 and 73 carry nylon-covered rollers 72c and 730 which, in the position of the levers shown in the drawing, grip the bag along a region parallel to and somewhat above the weld He.

The operating rod'70 terminates in a piston-(not shown) housed within the cylinder 78 which is connected to a suitable source of air pressure for controlling the movement of the rod towards the left or the right. In the drawing the rod is shown in the extreme right-hand position, in which position the rollers 72c and 730 grip the bag as previously explained. Movement ofthe rod towards the left from the position shown in the drawing is effective through links 75 and 76 in allowing the spring '74 to rotate the bell crank lever 72 in an anticlockwise direction and the bell crank lever 73 in a clockwise direction whereby the rollers 72c and 73c are separated.

The structure carrying the fixed stations is also provided, at the particular station being considered, with a sloping portion 64b which carries a tubular bearing 79 for a push rod 80. The upper end of the push rod is provided with a resiliently mounted dome 80a which engages with the underside of lever 35a (FIG. 9). As shown'in the drawing the dome is provided with an internal cylindrical cavity 80b into which extends the end of the push rod 80, a pin 800 in the dome working in a slot 80d in the push rod 80. A spring 80e is located between the upper end'of the cavity 8% and the upper end of the push rod 80, the tension of the spring being such that, in the position of the push rod 80 shown in the drawing, it has substantially no restraining elfect on the movement of back jaw 35. However, when the push rod is moved vertically and the spring 80:: is thereby compressed, the engagement between the dome 80a and the underside of lever 35a holds the lever 35a against any anticlockwise rotation about its pivot 35b. The purpose of this arrange ment will be described later.

The apparatus operates as follows. When the supporting means 30 for the bag is indexed to the station under consideration, the bag 11 is held in the support means with the face 11a of the bag against the back jaw 35 and with the side jaws 32 and 33 closed, the shoes 32a and 33a entering the gussets 11c and 11d of the bag. The operating rod 70 is at this time in its extreme left hand position so that the rollers 72c and 730 are separated. As the supporting means are indexed to the position shown, the lower regions of the bag are guided between the two rollers 72c and 73c and the upper regions of the bag come into substantially vertical alignment with nozzle 48 and directly opposite pad 60 on the pad carrier 55. As the cam shaft 52a rotates, cam follower 57 causes the bell crank lever 56a to rotate in an anticlockwise direction whereby pad 60 is advanced against the exposed face of the bag 11. During this displacement the electromagnet 65 is energised and is thereby attracted to the soft iron block 66 causing lever 63 to rotate in a clockwise direction to raise the beak 63a to its highest position; The coil spring 62 is holding the bearing bracket 61 in its forwardmost position and the beak 63a is therefore in advance of the resilient pad 60. At this time the operating rod 70 is moved to its extreme right-hand posi tion as shown in FIG. 13 and the rollers 72c and 730 approach each other to grip the bag at its lower regions. This position is shown in FIG. 2. In the forwardmost position of pad carrier 55, the electromagnet 65 releases and the lever 63 is rotated anticlockwise under the action of coil spring 64 such that the beak 63a enters into the open end of the bag. Cam follower 57 is then rotated by cam 55 in a clockwise direction to retract the pad carrier 55 with its associated parts and, in retracting, the beak 63a pulls the exposed wall 11b of the bag 11 outwardly from the supporting means causing the mouth of the bag 11 to be opened sufficiently to allow nozzle 48 to enter thereinto. This position is shown in FIG. 3.

Push rod 51 is then advanced by cam 52 and nozzle 48 is lowered into the open mouth of the bag 11 and, when this operation has been completed, the electromagnet 65 is again energised to withdraw the beak 63a from engagement with the bag. Cam 58 then allows cam follower 57 to be rotated in an anticlockwise direction to advance pad carrier 55 a second time, the forward displacement in this second movement being greater than in the first and resilient pad 60 engages the exposed wall of the bag to close the open mouth of the bag tightly about the nozzle 48 as shown in FIG. 7. During this second advance of said pad carrier 55, the beak 63a engages the nozzle 48 before the pad carrier 60 has completed its forward displacement and the lever 63, which is of substantially rigid construction, forces the bearing bracket 61 to be rearwardly displaced relatively to pad carrier 55 against the action of spring 62.

The nozzle 48 is then connected to the high pressure source and the high pressure gas is discharged from the nozzle 48 into the bag 11 to cause said bag to inflate. As gas is released into the bag 11 through the nozzle 48, the bag 11 becomes inflated over the region between jaws 32a, 33a, 35 and rollers 72c, 73c, rollers 72c and 73c preventing the pressure gas from entering into the lower regions of the bag 11 and the expansion of the bag 11 continues until the said section intermediate jaws 32a, 33a, 35 and rollers 72c, 73c is fully inflated as shown in FIG. 4. The inflation of the said section takes place before any substantial extraction of the lower regions of the bag 11 from between the rollers 72c, 73c.

It will be appreciated that the inflated section is held at the bag mouth by jaws 32c, 33c, 35 and at the lower end by rollers 72c, 730 so that the inflation of said section causes tension forces to develop in the plane faces 11a, 11b of the bag 11.

The inflation of the mid section in causing separation of the faces 11a, 11b also causes the gusseted side walls to open and near the mid region of the inflated section of the bag 11 may be inflated to its maximum section.

The continuous increase in gas pressure in the inflated section causes an increasing build up of tension foces in plane faces 11a and 11b and eventually the forces in the plane faces 11a and 11b exceed the force necessary to draw the collapsed lower regions of the bag 11 upwardly from between rollers 72c and 730 and the lower regions of the bag 11 are thereby drawn upwardly from between rollers.

Under the above conditions, i.e. the controlled release of the lower regions of the bag 11 from the nip of rollers 720 and 730, the build up of tension forces in the faces 11a and 1112, the gas force causing the faces 11a and 11b to move outwardly and the gusseted side walls 110 and 11d to be extended, coupled with the formation of the bottom closure of the bag 11, a folding action takes place at the lower regions of the bag 11 as they are released from the rollers 72c and 73c to form a block bottom thereby giving the container the shape shown in FIG. 5.

It has been found that during inflation of the bag, the high gas pressure used tends to cause rearward movement of the back jaw 35 and anticlockwise rotation of the lever 35a against the tension of the spring 36. This may cause leakage of gas through the upper end of the bag 11 to prevent this the push rod (FIG. 13) is moved vertically during the inflating operation to compress the spring 80a thereby preventing any anticlockwise rotation of the lever 3511 (FIG. 9) and backward movement of the jaw 35.

A second embodiment of the invention is shown in FIG. 6 in which the roller 720 is rotatably mounted on one end of a bell crank lever 21 pivotally attached near its mid region to a fixed mounting frame member 22 and lever 21 is maintained in a position abutting a fixed frame member 23 by a relatively strong tension spring 24. The roller 730 is rotatably mounted on one arm of a second bellcrank lever 25 which also has a mid-pivotal connection with member 22 and lever 25 has a roller 26 on the end of its lower arm member, roller 26 being engaged in a horizontal guide slot 27 in a block 28 secured to the top of a push rod 29.

It will be seen that with this arrangement roller 730 can be displaced away from the roller 720 when the push rod 29 is upwardly displaced to rotate the bell crank lever 25 clockwise as shown in FIG. 6 and when push rod 29 is downwardly displaced bell crank lever 25 is rotated anticlockwise so that roller 73c is advanced towards roller 720. The resilient mounting of the roller 16 enables a close control to be effected on the pressure between the rollers and therefore constitutes a control of the internal pressure in the bag 11 necessary to extract the lower regions of the bag 11 from between the rollers 72c and 730.

It will be understood that the various operations of the two embodiments shown in FIGS. 6 and 13 take place as part of the timed sequence of the machine as a whole, and apparatus for coordinating the different operations is not described since it is, in general, well known and does not form part of the present invention.

Further while the machine described in our Patent No. 3,112,588 uses semi-rigid material for the tubing, the invention is also applicable to the formation of block-bottom containers using material having non-rigid characteristics.

Many modifications and variations of the invention will be apparent to those skilled in the art and the invention is not restricted to the specific embodiments described and shown but covers all arrangements for forming a bag into a block bottom container by inflating the bag and causing the lower regions thereof to be drawn through a restricted opening by the forces developed in the bag walls during inflation.

I claim:

1. In apparatus for forming a container from a length of gusseted tubing having one end closed, the provision of block bottom forming means comprising support means for supporting the length of gusseted tubing in the region of the upper open end thereof, first and second members for defining a restricted opening in parallel relationship to the flat sides of the length of tubing at the lower regions thereof, through which restricted opening passes the closed end of said length of tubing and means for inflating the length of tubing at the open end thereof to form the container whereby the lower regions of said length of tubing are drawn upwardly through said restricted opening to enable a folding action to take place to give a block bottom to the container so formed.

2. Block bottom forming means as claimed in claim 1,

wherein said first and second members comprise freely rotatable nylon-covered rollers.

3.v Block bottom forming means as claimed in claim 1 wherein. said first. member comprises a freely rotatable resiliently mounted nylon-covered roller and said second member. comprises a freely rotatable nylon-covered roller, means being provided for moving said second-mentioned roller towards said resiliently mounted roller whereby the lower regions of the flat faces of the length of tubing are gripped between the rollers.

4. Block bottom forming means as claimed in claim 1 wherein said first and second members comprise freelyrotatable nylon-covered rollers and means are provided for moving said rollers towards one another whereby the lower regions of the flat faces of the length-of tubing are gripped between the rollers.

5.-In apparatus for forming a container from a length of gusseted tubing having one end closed, the provision of block bottom forming means comprising support means for supporting the length of gusseted tubing in the region of the upper open end thereof, a pair of freely rotatable-rollers positioned in parallel relationship to the flat sides of the length of tubing at the lower regions thereof and adjacent the closed end, means for moving at least one of said rollers to grip the length of tubing and means for inflating the length of tubing at the open endthereof to form the container whereby the lower regions of the length of tubing are drawn upwardly between the rotatable rollers to enable a folding action to take place to give a block bottom to the container so for-med.

6. Block bottom forming means as claimed in claim 5, wherein said rollers are nylon covered.

7. In apparatus for forming a container from a length of gusseted tubing having one end closed, the provision of block bottom forming means comprising support means for supporting the length of gusseted tubing in the region of its upper open edge, a pair of freely rotatable rollers positioned in parallel relationship to the flat sides of the supported length of tubing adjacent the closed end of said length of tubing, means for moving one of said rollers towards the second roller to grip the length of tubing and means for inflating the length of tubing at the open end thereof to form the container whereby the lower regions of the length of tubing are drawn upwardly between the rotatable rollers to enable a folding action to take place to give a block bottom to the container so formed.

8. Block bottom forming means as claimed in claim 7, wherein said rollers are nylon covered.v

References Cited by the Examiner UNITED STATES PATENTS 1,886,376 11/1932 Dambacher 53-385 2,917,217 12/1959 Sisson.

BERNARD STICKNEY, Primary Examiner. 

5. IN APPARATUS FOR FORMING A CONTAINER FROM A LENGTH OF GUSSETED TUBING HAVING ONE END CLOSED, THE PROVISION OF BLOCK BUTTOM FORMING MEANS COMPRISING SUPPORT MEANS FOR SUPPORTING THE LENGTH OF GUSSETED TUBING IN THE REGION OF THE UPPER OPEN END THEREOF, A PAIR OF FREELY ROTATABLE ROLLERS POSITIONED IN PARALLEL REALTIONSHIP TO THE FLAT SIDES OF THE LENGTH OF TUBING AT THE LOWER REGIONS THEREON AND ADJACENT THE CLOSED END, MEANS FOR MOVING AT LEAST ONE OF SAID ROLLERS TO GRIP THE LENGTH OF TUBING AND MEANS FOR INFLATING THE LENGTH OF TUBING AT THE OPEN END THEREOF TO FORM THE CONTAINER WHEREBY THE LOWER RE- 